This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. SIV DNA vaccines and mucosal immunity More than 80% of global transmission of HIV infection occurs via mucosal routes. The ability of vaccines to induce mucosal immunity may be required for protection against HIV infection and the immunodeficiency syndrome that emerges after infection. Various AIDS vaccine candidates are currently under development, each with potential advantages and disadvantages. DNA vaccines have features that make them attractive vaccine candidates for HIV and the combination of DNA vaccination plus recombinant vaccinia is one of the favored approaches in AIDS vaccine development.